Concerning C.H. crockery, I have a very clear memory of a curious incident. At some time in the early 1950s we were suddenly provided with clear plastic mugs for water at lunch. This was the first attempt at any sort of modernisation and we were very impressed. BUT, after a few days there started to be examples of spontaneous explosion by these mugs - a sudden bang and instant disintegration - always when empty. Although the mugs disintegrated it was not dangerous as the bits were all smooth edged. Also, there was no question of them being caused by destruction-minded boys. These new mugs disappeared overnight and were quickly forgotten, but I have never heard an explanation of his peculiar phenomenon.
David

Some plastics(even now) are unstable and can break. It seems to be a parallel to metal fatigue. Some causes are heat, great cold, UV rays. Perhaps it was the industrial dish washers or even the cleaning agent.

Sometimes I’m right. Other times my wife is close enough to hear what I’m saying.

When acrylic 'glasses' first became available my mother was in a store where they were demonstrating how tough they were, by throwing them on the floor with no ill effect. She was so impressed that she bought some. As soon as she got home she called us all into the kitchen and, with a triumphant "Watch this!", threw one on the floor whereupon it shattered onto a thousand shards. Not sure is she was really angry and letting off steam, or had had suffered some kind of seizure, we stood there in silence. It didn't help that my mother became so irate that for several minutes all she could do was stamp on the pieces and muttering to herself. Eventually a stiff drink and some time to recover let her explain the sequence of events, but for years afterwards any new item in the house was always greeted with the question "Is it unbreakable?"

If a stone falls on an egg: alas for the egg
If an egg falls on a stone: alas for the egg

,,, BUT, after a few days there started to be examples of spontaneous explosion by these mugs - a sudden bang and instant disintegration - always when empty. Although the mugs disintegrated it was not dangerous as the bits were all smooth edged.

My memory is a little different, as memories tend to be. I remember those glasses bursting spontaneously, exactly as described, and shattering into hundreds of fragments with no sharp edges. But I recall them as real glass, of some "toughened" variety that was then being touted for windsreens and the like. "Toughening" seemed to involve pre-stressing, so that any minor injury to the glass might release all the energy stored in it in an instant, which explains (in my mind) why the fragments flew so far instead of simply falling. I do believe that we saw the boxes these glasses arrived in, and they bore the name of some well-known glass brand.